"This approach is capable of seeing extremely small objects and discovering things we never thought existed about these materials and their uses."Edwin Fohtung, Rensselaer Polytechnic Institute
When scientists and engineers discover new ways to optimize existing materials, it paves the way for innovations that make everything from phones and computers to medical equipment smaller, faster and more efficient.
A group of researchers – led by Edwin Fohtung, an associate professor of materials science and engineering at Rensselaer Polytechnic Institute – has found a new way to optimize nickel by unlocking properties that could lead to numerous applications, from biosensors to quantum computing.
As reported in a paper in NPG Asia Materials, the researchers demonstrated that when nickel is made into extremely small, single-crystal nanowires and subjected to mechanical energy, a huge magnetic field is produced, a phenomenon known as giant magnetostriction. Inversely, if a magnetic field is applied to the material, then the atoms within will change shape, which could be exploited to harvest energy.
According to Fohtung, that characteristic could also be useful for data storage and data harvesting, even biosensors. Though nickel is a common material, its promise in these areas wasn't previously known.
"Imagine building a system with large areas of nanowires. You could put it in an external magnetic field and it would harvest a very huge amount of mechanical energy, but it would be extremely small," Fohtung said.
The researchers uncovered this unique property through a technique called lensless microscopy, in which a synchrotron is used to gather diffraction data. That data is then plugged into computer algorithms to produce three dimensional images of electronic density and atomic displacement.
Using a big data approach, Fohtung said, this technique can produce better images than traditional microscopes, providing researchers with more information. It combines computational and experimental physics with materials science – an intersection between Fohtung’s multiple areas of expertise.
"This approach is capable of seeing extremely small objects and discovering things we never thought existed about these materials and their uses," Fohtung said. "If you use lenses, there's a limit to what you can see. It's determined by the size of your lens, the nature of your lens, the curvature of your lens. Without lenses, our resolution is limited by just the wavelength of the radiation."
Fohtung used the same technique to show that barium hexaferrite – a universal and abundant material often used in tapes, CDs and computer components – possesses spontaneous magnetic and electric polarization that increases and decreases when exposed to an electric field. This property, known as ferroelectricity, is useful for fast-writing, power-saving and data storage. Together with colleagues, Fohtung recently reported these findings in a paper in Physical Review B.
Fohtung believes that the lensless approach to studying substances will allow researchers to learn even more about solid-state materials, like those used in technological devices. It may even allow a deeper understanding of human tissue and cells, which could be viewed in a more natural habitat using this technique.
"What excites me so much about it is the potential for the future. There are so many existing materials that we are just not able to understand the potential applications," Fohtung said.
This story is adapted from material from Rensselaer Polytechnic Institute, with editorial changes made by Materials Today. The views expressed in this article do not necessarily represent those of Elsevier. Link to original source.